Method of introducing an additive into a fluid system, especially useful for leak detection, as well as an apparatus for leak detection and a composition useful for leak detection

• US 6,170,320 B1
• Filed: 04/10/1998
• Issued: 01/09/2001
• Est. Priority Date: 01/24/1997
• Status: Expired due to Term

• Current Assignee: Mainstream Engineering Coporation
• Original Assignee: Mainstream Engineering Coporation
• Inventors: Back, Dwight D., Mayer, Joseph, Scaringe, Robert P., Grzyll, Lawrence R.
• Primary Examiner(s): WU, SHEAN CHIU
• Application Number:
  US09/058,254
• Time in Patent Office: 1,005 Days
• Field of Search: 252/964, 252/67, 252/301.19, 73/40, 73/405, 735/92, 73/407, 436/3
• US Class Current: 73/40.7
• CPC Class Codes: F25B 2500/222 Detecting refrigerant leaks
• CPC Class Codes: G01M 3/20 using special tracer materials, e.g. dye, fluorescent material, radioactive material
• CPC Class Codes: G01M 3/228 for radiators
• CPC Class Codes: G01M 3/38 by using light G01M3/02 takes precedence
• CPC Class Codes: Y10S 252/964 Leak detection

Abstract

An additive is introduced into a fluid system and dissolved in a carrier fluid which is immiscible or slightly miscible in the fluid system, wherein the carrier fluid is subsequently removed from the fluid system. This method can be used to detect leaks, wherein an on-off UV light source, such as xenon light, can be used to detect the leak visually.

Claims

1. A method of introducing an additive into a system comprising a system fluid, the additive comprising at least one compound, comprising the steps of

dissolving the additive in a carrier fluid, wherein the carrier fluid is immiscible or slightly miscible in the system fluid,

delivering the additive and the carrier fluid into the system, and

removing the carrier fluid from the system fluid, leaving the additive dissolved in the system fluid.

2. The method of claim 1, further comprising the step of delivering an amount of the additive into the system in concentrations of up to the solubility limit of the additive in the system fluid.

3. The method of claim 1, wherein the additive comprises at least one compound which is soluble in the system fluid and the carrier fluid, and has fluorescent properties.

4. The method of claim 1, wherein the additive comprises at least one organic compound which emits color in the visible spectrum.

5. The method of claim 1, wherein the additive comprises at least one fluorescent compound and at least one organic compound which emits color in the visible spectrum.

6. The method of claim 1, wherein the system fluid comprises PAG, POE, mineral oil or AB.

7. The method of claim 1, wherein the carrier fluid comprises alcohol.

8. The method of claim 1, wherein the carrier fluid comprises at least one of ethanol, methanol, and 2-propanol.

9. The method of claim 1, wherein the additive comprises a molecule comprising at least one cyclic group, said molecule comprising atoms selected from the group consisting of C, H, halogens, S, N, and O.

10. The method of claim 1, wherein the additive comprises an organo-metallic compound.

11. The method of claim 1, wherein the additive comprises an inorganic compound.

12. The method of claim 1, wherein the additive is selected from the group consisting of coumarin and derivatives thereof, where G represents groups comprising at least one of C, H, halogens N, and S, and j greater than or equal to 0:

13. The method of claim 1, wherein the additive is selected from the group consisting of phenylnaphthylamines, where R₁, R₂, and R₃ are groups comprising at least one of C, H, halogens, N, S, and O in cyclic or acyclic structures:

14. The method of claim 1, wherein the additive is selected from the group consisting of diphenylamines, where R₄ and R₅ are groups comprising at least one of C, H, halogens, N, S, and O in cyclic or acyclic structures:

15. The method of claim 1, wherein the additive is selected from the group consisting of benzothiazolines, where R₆, R₇, R₈ and R₉ are groups comprising at least one of C, H, halogens, N, S, and O in cyclic or acyclic structures:

16. The method of claim 1, wherein the additive is selected from the group consisting of benzothiazoles, where R₁₀ and R₁₁ are groups comprising at least one of C, H, halogens, N, S, and O in cyclic or acyclic structures:

17. The method of claim 1, wherein the additive is an additive selected from the group consisting of anti-oxidation, anti-wear, anti-friction, dispersion improvement, and viscosity index improvement additives.

21. The method of claim 17, wherein the carrier fluid comprises alcohol.

22. The method of claim 17, wherein the carrier fluid comprises at least one of ethanol, methanol and 2-propanol.

26. The method of claim 21, wherein the carrier fluid comprises alcohol.

27. The method of claim 21, wherein the carrier fluid comprises at least one of ethanol, methanol and 2-propanol.

39. The method according to claim 1, further comprising the step of detecting a leak in the system with a flashing UV lamp.

40. The method according to claim 39, the flashing UV lamp, a xenon flash tube, a trigger circuitry means for obtaining an adjustable or a preset flash rate and a filter glass.

41. The method according to claim 40, wherein the xenon flash tube comprises an ultraviolet flash pulse circuit.

42. The method according to claim 40, wherein the xenon flash tube comprises an UV flash pulse circuit.

43. The method according to claim 40, wherein the mean produces a flash rate from about 4 flashes per second to about 1 flash every four seconds.

44. The method according to claim 40, wherein the filter is applied directly to the xenon flash tube.

18. A leak detection method, comprising the steps of introducing a compound selected from the group consisting of organo-metallic compounds comprising at least one metal and at least one cyclic or acyclic structure comprising atoms selected from the group consisting of C, H, N, S, and O, wherein the at least one cyclic or acyclic group optionally includes at least one attached cyclic or acyclic structure comprised of atoms selected from the group consisting of C, H, halogens, N, S, and O into a refrigeration system comprising a fluid system, and causing the compound to fluoresce at any point in the system where there is a leak wherein the step of introducing comprises dissolving the compound in a carrier fluid, delivering the compound and the carrier fluid into the system, and removing the carrier fluid from the system fluid.

19. The method of claim 18, wherein the step of introducing the compound into the system is effected in concentration up to the solubility limit of the compound in the system fluid.

20. The method of claim 18, wherein the system fluid comprises PAG, POE, mineral oil or AB.

23. A leak detection method comprising the step of introducing a compound capable of fluorescing into a refrigeration system having a system fluid, and causing the compound to fluoresce at any point in the system where there is a leak, wherein the compound is soluble in the system fluid and comprises at least one of phenylnaphthylamines:

where R₁, R₂, and R₃ are groups comprising at least one of C, H, halogens, N, S, and O in cyclic or acyclic structures;

dialkyldiphenylamines;

where R₄ and R₅ are groups comprising at least one of C, H, halogens, N, S, and O in cyclic or acyclic structures;

organometallic compounds comprising molecular groups comprising at least one metal and at least one cyclic or acyclic structure comprising atoms selected from the group consisting of C, H, N, S, and O, wherein the at least one cyclic group optionally has at least one attached cyclic or acyclic structure comprised of C, H, halogens, N, S, and O;

benzothiazolines;

where R₆, R₇, R₈ and R₉ are groups comprising at least one of C, H, halogens, N, S, and O in cyclic or acyclic structures; and

benzothiazoles;

where R₁₀, and R₁₁ are groups comprising at least one C, H, halogens, N, S, and O in cyclic or acyclic structures wherein the step of introducing comprises dissolving the compound in a carrier fluid, delivering the compound and the carrier fluid into the system, and removing the carrier fluid from the system fluid.

24. The method of claim 23, wherein the step of introducing the compound into the system is effected in concentrations of up to the solubility limit of the compound in the system fluid.

25. The method of claim 23, wherein the system fluid comprises PAG, POE, mineral oil or AB.

28. A method of detecting leaks in a refrigeration system comprising a fluid system, comprising the steps of introducing a fluorescing compound dissolved in a carrier fluid into the fluid system, wherein the carrier fluid is immiscible or slightly miscible in the system fluid, delivering the dissolved fluorescing compound and the carrier fluid into the fluid system, and detecting the leak with a UV lamp.

29. The method of claim 28, further comprising the step of removing the carrier fluid from the system fluid.

30. The method of claim 29, wherein the carrier fluid comprises alcohol.

31. The method of claim 29, wherein the carrier fluid comprises at least one of ethanol, methanol and 2-propanol.

32. The method of claim 28, wherein the UV lamp is a xenon flash tube.

33. The method of claim 32, wherein the xenon flash tube comprises a quartz glass.

34. The method of claim 32, wherein the xenon flash tube is filled with a xenon gas mixture at a pressure of less than about 4 atmospheres.

35. The method of claim 32, wherein the xenon flash tube comprises a trigger circuitry means for obtaining an adjustable or a preset flash rate.

36. The method of claim 35, wherein the means produces a flash rate from about 4 flashes per second to about 1 flash every four seconds.

37. The method of claim 32, wherein the xenon flash tube comprises a filter glass with a high degree of internal transmittance in the 180 to 390 nm ultraviolet wavelength range.

38. The method of claim 32, wherein the xenon flash tube comprises an ultraviolet flash pulse circuit.